KD-HT
Also called: KD HT, kiln dried heat treated, HT-KD
KD-HT indicates wood that is both kiln dried (KD), dried to a target moisture content, and heat treated (HT) to ISPM 15. Only HT is an ISPM 15 treatment code; KD describes moisture and does not by itself make a pallet export compliant.
In depth: Heat treated vs kiln dried pallets: what the stamps mean
HT and KD answer different questions. HT asks: was the wood hot enough, long enough, to kill pests? KD asks: how much water is left in the wood?
KD vs HT
| Kiln dried (KD) | Heat treated (HT) | |
|---|---|---|
| Purpose | Reduce moisture content | Kill pests for ISPM 15 |
| Specification | Target moisture, e.g. 19% | 56 °C core for 30 continuous minutes |
| ISPM 15 code | None | HT |
| Prevents mold | Helps, while wood stays dry | No |
A kiln-drying run can also meet HT if it satisfies the HT parameters under an approved program. That is why "KD-HT" appears: one process, two results.
Why it matters
Heat-treated but green wood can still grow mold in a container. Buyers who ship food, pharmaceuticals or goods in sealed containers often want both: HT for compliance and KD for moisture. Costco, for example, requires moisture content under 19% for containerized shipments.
On a spec sheet or RFQ
Specify them separately: "ISPM 15 HT" and "kiln dried to 19% maximum moisture content (or your target), verified by moisture meter". PDS records drying as "Conditioning", for example "Kiln Dried – 19% EMC".
Common confusions
A "KD" stamp alone is not export compliance. Look for the IPPC mark with HT.
Related
- ComparisonsHeat treated vs kiln dried pallets: what the stamps meanHeat treatment (HT) heats the wood core to at least 56 °C for 30 minutes to meet ISPM 15 for export. Kiln drying (KD) lowers moisture content, typically to 19% or less, to reduce mold, shrinkage and weight. Choose HT for international shipping, KD for moisture control, and KD-HT when you need both.
- GlossaryWhat is heat treatment (HT) for pallets?Heat treatment (HT) is the ISPM 15 method of heating wood packaging until the whole profile of the wood, including its core, reaches at least 56 °C for 30 continuous minutes. Treated pallets carry the IPPC mark with the code HT.
- GlossaryWhat does kiln-dried mean for pallets?Kiln-dried (KD) lumber has been dried in a heated kiln to a target moisture content, most often 19% or less (KD19). Kiln drying reduces weight, shrinkage and mold risk, but a KD stamp alone does not show ISPM 15 compliance.
- GlossaryMoisture content (pallet lumber)Moisture content (MC) is the weight of water in wood expressed as a percentage of the wood's oven-dry weight. Pallet specs usually call for 19% or less when dry wood is needed; green lumber is above about 28%.
- GuidesPallet lumber moisture: green vs kiln-dried, shrinkage, weight and moldGreen pallet lumber can hold 50–80% moisture; kiln-dried (KD) lumber is dried to about 19% or less. Drier wood is lighter, stiffer and far less prone to mold, but green wood nails more easily and costs less. Heat treatment (HT) for ISPM 15 kills pests; it does not dry the pallet. Specify moisture separately.
More in Standards and compliance
- GlossaryCP palletCP pallets (chemical pallets) are a family of nine standardized wood block pallets, CP1 to CP9, developed for the European chemical and plastics industries. Each type has a defined size and construction for loads such as bagged polymer, drums and bulk containers.
- GlossaryDebarked lumberDebarked lumber is wood from which the bark has been removed. ISPM 15 requires all treated wood packaging to be made of debarked wood, allowing only small pieces of bark: under 3 cm wide of any length, or wider pieces with a surface area under 50 cm² each.
- GlossaryDielectric heating (DH)Dielectric heating (DH) is an ISPM 15 treatment that heats wood packaging with microwaves or radio waves until the entire profile of the wood, including its surface, reaches at least 60 °C for 1 continuous minute. Treated wood is marked with the code DH.
- GlossaryEPALEPAL (European Pallet Association e.V.) is the organization that licenses manufacturers and repairers of EPAL Euro pallets and other EPAL load carriers and controls their quality. The EPAL 1 Euro pallet is a 1200 × 800 × 144 mm block pallet used in open pallet exchange across Europe.
- GlossaryFSMA (Food Safety Modernization Act)FSMA is the US Food Safety Modernization Act of 2011. Under its Sanitary Transportation of Human and Animal Food rule (21 CFR Part 1, Subpart O), pallets are transportation equipment and must be designed and maintained so they are suitable and adequately cleanable, and do not make food unsafe.
- GlossaryGMAGMA stands for the Grocery Manufacturers Association (now the Consumer Brands Association), whose name became attached to the standard 48 × 40 in (1219 × 1016 mm) US grocery pallet: a partial four-way wood stringer pallet with three notched stringers, seven top and five bottom deckboards.
Last reviewed 2026-09-24. 223 words.